Apparatus and method for producing shrink-wrapped bundles

ABSTRACT

The invention includes an apparatus and a method for producing shrink-wrapped bundles ( 38 ) from groups ( 10 ) of assembled articles or containers ( 12 ). Assigned to a transport route ( 14 ) is a film application device ( 16 ) for wrapping the respective article groups or container groups ( 10 ) into a length of film ( 20 ) in the direction of transport ( 18 ) under formation of an overlapping section ( 22 ) as well as under formation of folding flaps ( 24 ) respectively projecting beyond the article groups or container groups ( 10 ) on the sides of the transverse edges. Mechanical folding members ( 26 ) serve for placing on top of each other the folding flaps ( 24 ) projecting on both transverse sides against the adjacent outer surfaces of the articles or containers, wherein an opening ( 32 ) is formed, in particular, between trailing edges ( 30 ) of the folding flaps ( 24 ), which trailing edges ( 30 ) face toward each other. In a heating section ( 34 ), the folded folding flaps are held in their respective position, and the film wrapping ( 20 ) is impinged with hot air for the purpose of forming shrink bundles ( 38 ). The mechanical folding members ( 26 ) for fixing the folded folding flaps ( 24 ) and/or for holding the folding flaps ( 24 ) in their folded position extend into the heating section ( 34 ) at least over a partial section ( 42 ) of a defined length ( 44   a,    44   b ).

CLAIM OF PRIORITY

This application is a continuation-in-part of U.S. patent application Ser. No. 15/068,804, filed on Mar. 14, 2016, which in turn claims the benefit of German Application Number DE 10 2015 103 919.2, filed on Mar. 17, 2015, all of which are incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to an apparatus and a method for producing shrink-wrapped bundles from assembled article groups or container groups.

BACKGROUND OF THE INVENTION

For packaging articles, such as plastic containers, methods and apparatuses are known from prior art which use a shrink film as outer packaging for the articles or containers, respectively. The shrink film is generally wrapped around the set of articles in the form of a length of film by means of a wrapping system. This so-called film-wrapped bundle is transported through a shrink tunnel. In the shrink tunnel, the wrapped articles are impinged with a shrinking medium, for example with warm or hot air, thus causing the shrink film to contract such that it fits closely to the articles, stabilizes them and holds them together. After passing through the heat treatment, the film-wrapped bundle is also termed shrink bundle.

Such a method for forming shrink-wrap packages follows from DE 10 2006 036 590 A1, for instance.

Since the film web is shortened in the process of shrinking, and since a limited length of film is used for each bundle in order to prevent undesired folding from occurring, open lateral areas normally form, which are also termed shrink eyes or film eyes. On the one hand, these shrink eyes can lead to disadvantages in the mechanical stability of the shrink bundles, one the other hand, they can lead to optical impairments or to irregularities, respectively, in the design of the shrink bundle.

Different methods have already been proposed for the purpose of preventing such undesired film eyes and for forming bundles that are completely enclosed by a film wrap on all sides. WO 2012/149947 A1 thus discloses a method for packaging groups of objects assembled into packaging units, which are each wrapped into a film in their direction of movement on a transport route, in which method a film overlap as well as folding flaps respectively projecting beyond the packaging unit at the transverse edges are formed at the same time. The packaging unit subsequently passes through a folding unit, where the folding flaps are placed against the packaging unit and, as the case may be, are fixed to one another, thus forming a film wrap that is closed on all sides.

A similar method for producing packaging units wrapped into film that is closed on all sides follows from EP 2 219 954 B1.

Apparatuses for packaging such packaging units and for placing film overlaps against the packaging units can be found in DE 10 2012 016 698 A1 and in DE 10 2012 016 699 A1.

DE 10 2010 032 455 A1 discloses a shrinking apparatus and a method for shrinking a shrink film onto containers, which are being moved along a transport route in the form of a packaging unit. The distance of the heat sources used for shrinking to the packaging unit is variably adjustable and it is adjusted during the shrinking process in accordance with the dimensions of the packaging unit, which dimensions can vary, as the case may be.

Since folding and fixing the folded and overlapping lengths of film, however, involves a relatively high additional mechanical effort in the construction of existing packaging machines, and since film wraps that are closed on all sides can have further disadvantages for shrink bundles in individual cases, there are many application instances, in which it is desirable to continue to provide shrink eyes in the production of the shrink bundles.

SUMMARY OF THE INVENTION

The primary object of the present invention is therefore seen in providing an efficient and largely automatable method for producing shrink-wrapped bundles, which method neither complicates, nor in any way impairs, nor slows down the packaging process. In addition, an object of the invention lies in providing a corresponding apparatus for producing shrink-wrapped bundles.

These objects are achieved by the subject matter of the independent claims. Features of advantageous developments are indicated in the respective dependent claims.

In order to achieve the stated object, the invention proposes a method for producing shrink-wrapped bundles from groups of assembled articles or containers, the method having the features of the independent method claim 1. In this method, the article groups or container groups to respectively be packaged are wrapped into a length of film in the direction of transport on a transport route under formation of an overlapping section as well as under formation of folding flaps respectively projecting beyond the article groups or container groups on the sides of the transverse edges. Subsequently, the folding flaps projecting on both transverse sides are at least partially placed on top of each other and/or are placed against the adjacent outer surfaces of the articles or containers by means of mechanical folding members and under formation of an opening or under largely closing the transverse sides between trailing edges of the folding flaps, which trailing edges face toward each other. In the method, the article groups or container groups together with the film wrapping furthermore pass through a heating section under formation of shrink bundles, in which heating section the article groups or container groups, which have been wrapped in film, are impinged with hot air. In this process, at least a part of the folded folding flaps are fixed and/or held in their folded position over a defined length within the heating section by means of the mechanical folding members such that the previously achieved folding state is at least maintained over a first section of the heating section. The mechanical folding members extend into the heating section in the direction of transport at least up to where a shrinking process impinging the respective wrapped container groups or article groups has started and the lengths of film, which are placed on top of each other, cling to one another.

A particularly advantageous variant of the method according to the invention provides that the folding members each comprise guide bars on at least one longitudinal side of the transport route or that they are formed by such guide bars. Such guide bars can provide in an efficient manner for achieving a folding state of the folding flaps projecting beyond the article groups or container groups on the sides of the transverse edges, which folding flaps are placed on top of each other there, or for maintaining this folding state into the heating section, respectively, such that the shrinking process can be carried out with precisely positioned folding flaps. Optionally, the guide bars arranged on at least one longitudinal side of the transport route can be designed to be height-adjustable and/or so that they can be adjusted in their horizontal position in relation to the transport route for the purpose of adjusting to different sizes of articles or containers. For adjusting to different bundle sizes, a width adjustment is, in particular, necessary. Also possible are variants in which two or more guide bars are provided, arranged at least on one longitudinal side of the transport route in parallel on top of one another and spaced apart from each other, which guide bars can provide for pressing the folding flaps evenly against the respective article groups or container groups along their entire height. Although it is conceivable for the guide bars to be designed differently on the left and on the right side, a longitudinally symmetric construction is typically provided, with the guide bars to the left and the right side of the transport route being respectively designed and positioned in an approximately identical manner.

In one variant of the method according to the invention, the mentioned guide bars can be provided with air exit openings such that air exits through openings from the guide bars, which extend on at least one longitudinal side of the transport route and/orinto the heating section. On the one hand, this air can serve as cooling air for preventing the film flaps of the article groups or container groups, which have been wrapped in film, from adhering or clinging to the guide bars. On the other hand, the air also serves as an air cushion, which can likewise reliably prevent such an adhesion. In addition, the air streaming out of the openings can reduce the friction of the article groups or container groups that glide along the guide bars.

According to a further embodiment variant of the method according to the invention, the folding members can respectively comprise movable wrapping members or they can be at least partially formed by such movable wrapping members. In this context, the movable wrapping members can comprise, for instance, at least one pivoting lever, which is arranged on at least one side of the transport route such as to be pivotable about an approximately horizontal pivoting axis. A reasonable pivoting radius of the wrapping members can reach approximately from a vertical position to an approximately horizontal position aligned approximately in parallel to the conveying direction. According to the prevailing installation conditions and according to the selected drive variant, however, larger pivoting ranges can also be reasonable. Alternatively, the pivoting levers can also be arranged to be rotationally movable so that they continuously rotate about horizontal rotation axes. If these wrapping members or so-called wrapper members, respectively, are each formed by pivotable folding fingers with the specified radius of movement, they can place at least the rear folding flaps, as viewed in the direction of transport, to the front over the previously folded folding flaps by a pivoting motion or by a rotary movement, respectively, preferably immediately before the entrance of the heating section, such that the desired enclosing folding state can be produced, which, during the shrinking process in the heating section, will then lead to the desired adhesion of the folding flaps to one another, which folding flaps have been placed on top of each other. When doing without the movable wrapping members, it is reasonable to take other suitable measures for folding over at least the folding flaps at the rear side, as viewed in the direction of transport, to the front, since precisely these folding flaps can otherwise be easily folded over to the back by the transport of the article groups or container groups, which is not desired and which would inevitably lead to an impairment of the packaging quality of the shrink-wrapped bundles to be produced.

Much like the rigid guide bars or the guide bars, respectively, which are designed to be height-movable, the movable wrapping members can also be designed to be adjustable in their vertical and/or horizontal position in relation to the transport route. The adjustability in height and/or width is reasonable for the purpose of adaptability to the different sizes of articles or containers, to the different sizes or widths of bundles, etc., which are intended to pass through the heating section.

The method provides that the guide bars extend into the heating section by a defined length. The guide bars can optionally be passed through the entire heating section, or also only through a partial section, since it may suffice, as the case may be, if the folding flaps, which have been placed on top of each other, are not pressed against each other throughout the entire heating section. Optionally, the length of the guide bars can also be variably adjustable.

It is furthermore reasonable for the movable wrapping members and/or for the guide bars, which extend into the heating section, to be respectively formed to be heat-resistant and/or to be provided with a heat-resistant coating. In this manner, it is possible to prevent the heated shrink film from adhering to the guide bars and/or to the adjustable wrapping members and thereby from leading to either the folding state to be impaired or even to the film to be damaged. Embodiment variants that are cooled and/or lubricated are moreover conceivable. The guide bars can thus be formed to be hollow, for instance, such that a cooling liquid can circulate inside, which can provide for the desired tempering or cooling, respectively, of the guide bars. Lubrication can be supplied, for instance, by providing small exit openings at the guide bars for the purpose of a loss lubrication with a suitable lubricant. By way of suitable apparatuses, the lubricant can exit at the surfaces of the guide bars at definable intervals and in a desired quantity.

The method can optionally provide that at least individual folds are fastened, glued, or welded onto one side or onto both transverse sides of the film-wrapped bundles. This fastening, gluing, or welding can be carried out for individual folding flaps, for instance, for the top, bottom, and/or lateral folding flaps, or also for a plurality of folding flaps. In this manner, the shrinking is supported by the folding flaps, which have been placed on top of each other, additionally being fixed to one another.

According to a preferred embodiment variant, the method according to the invention provides a defined folding sequence, in which the respectively top folding flaps of the film-wrapped article groups or container groups are held in their unwrapped or unfolded position, respectively, at least until folding or wrapping, respectively, the remaining folding flaps of each side, and they are only subsequently placed laterally against the article group or container group. In this manner, it is possible to reliably prevent disordered folding processes in which the top folding flaps, for instance, can fold down, in particular, while the lateral, i.e. the front and/or the rear folding flaps are being wrapped, and interfere with these folding processes or lead to wrinkles, respectively. If the top folding flaps are, however, held up by means of suitable devices for as long until the remaining folding flaps have been placed against the film-wrapped article groups or container groups, such potential disruptions are prevented. The fixation of the top folding flaps can be ensured by way of suitable suction devices, for instance, or optionally also by electrostatic holding force, mechanical holding force, or the like. Optionally, the top folding flaps can be held in their upper, as yet unfolded position by way of being blown at with compressed air until the remaining folding flaps have been placed against the article groups or container groups, after which the top folding flaps can then also be placed against the article groups or container groups as the last ones, after which the folds can be fastened, glued, or also welded, for example, as the case may be.

A particularly reasonable folding process of the lateral overlapping sections of the length of film, which has been placed around the respective article group or container group, provides that first the front and the rear folding flaps are folded over, after which the bottom folding flaps on both sides and only subsequently and last the top folding flaps on both sides are folded over, optionally respectively supported by suitable mechanical folding members or guide bars, respectively, and/or by fixing devices or holding devices, respectively, in particular for holding the top folding flaps in their horizontal position.

As already mentioned above, the folding flaps, which have been placed on top of each other on the sides of the transverse edges, can optionally be placed overlappingly on top of each other in such a manner that a completely enclosed shrink bundle is produced. Variants are likewise possible, however, in which the folding flaps do not completely overlap such that lateral openings, which are typically termed film eyes, remain.

Furthermore, the method allows providing up to four conveyor lines arranged adjacent to each other and respectively having folding members of the same type. In this instance, guide bars and/or movable folding members can be respectively arranged in multiple numbers for up to four parallel conveyor tracks if the heating section is also designed correspondingly wide for receiving up to four article groups or container groups being conveyed in parallel.

In order to achieve the stated object, the invention furthermore proposes an apparatus for producing shrink-wrapped bundles from groups of assembled articles or containers, the apparatus having the features of the independent claim 9. This apparatus comprises a transport route to which a film application device is assigned. The film application device serves for wrapping the respective article groups or container groups into a length of film in the direction of transport, in which process an overlapping section with folding flaps respectively projecting beyond the article groups or container groups on the sides of the transverse edges is formed at the same time. The apparatus furthermore comprises mechanical folding members for at least partially placing on top of each other the folding flaps projecting on both transverse sides against the adjacent outer surfaces of the articles or containers. In this process of placing folding flaps on top of each other, an opening can optionally be formed between trailing edges of the folding flaps, which trailing edges face toward each other. It is, however, likewise possible that the trailing edges facing toward each other are placed on top of each other such that they overlap each other and form closed sides without openings. Downstream from the film application device, as viewed in the direction of transport, the transport route has a heating section for impinging the article groups or container groups together with the film wrapping with hot air for the purpose of forming shrink bundles. The mechanical folding members for fixing the folded folding flaps and/or for holding the folding flaps in their folded position extend into the heating section at least over a partial section of a defined length.

A particularly preferred variant of the apparatus according to the invention provides that the folding members each comprise guide bars on at least one longitudinal side of the transport route or that they are formed by such guide bars. These guide bars can provide in an efficient manner for achieving a folding state of the folding flaps projecting beyond the article groups or container groups on the sides of the transverse edges, which folding flaps are placed on top of each other there, or for maintaining this folding state into the heating section, respectively, such that the shrinking process can be carried out with precisely positioned folding flaps. Optionally, the guide bars arranged on at least one longitudinal side of the transport route can be designed to be height-adjustable and/or so that they can be adjusted in their horizontal position in relation to the transport route for the purpose of adjusting to different sizes of articles or containers. For the purpose of adjusting to different bundle sizes or widths, respectively, a width adjustment or an adjustment of the distance of the guide bars to each other, respectively, is, in particular, necessary. Also possible are variants in which two or more guide bars are provided, arranged at least on one longitudinal side of the transport route in parallel on top of one another and vertically spaced apart from each other, which guide bars can provide for pressing the folding flaps evenly against the respective article groups or container groups along their entire height. Although it is conceivable for the guide bars to be designed differently on the left and on the right side, a longitudinally symmetric construction is typically provided, with the guide bars to the left and the right side of the transport route, respectively, being designed and positioned in an approximately identical manner.

According to a further embodiment variant of the apparatus according to the invention, the folding members can respectively comprise movable wrapping members or they can be at least partially formed by such movable wrapping members. In this context, the movable wrapping members can comprise, for instance, at least one pivoting lever, which is arranged on at least one side of the transport route so as to be pivotable about an approximately horizontal pivoting axis. In order to avoid a clocked mode of operation of the apparatus, these pivoting apparatuses can be designed to rotate, with the wrapping process comprising a part of a 360 degrees movement of the pivoting apparatus or of the pivoting lever, respectively. Such continuous processes with continuously rotating parts are usually more reliable in continuous operation than drives that function in an oscillating manner. A reasonable pivoting radius of the wrapping members can reach approximately from a vertical position to an approximately horizontal position aligned approximately in parallel to the conveying direction. If these wrapping members or so-called wrapper members, respectively, are each formed by pivotable or rotating folding fingers, respectively, with the specified radius of movement between approximately 90 degrees for an oscillating movement and 360 degrees for a rotating movement, they can place at least the rear folding flaps, as viewed in the direction of transport, to the front over the previously folded folding flaps by a pivoting motion, preferably immediately before the entrance of the heating section, such that the desired enclosing folding state can be produced, which, during the shrinking process in the heating section, will then lead to the desired adhesion of the folding flaps to one another, which folding flaps have been placed on top of each other. When doing without the movable wrapping members, it is reasonable to take other suitable measures for folding over at least the folding flaps at the rear side, as viewed in the direction of transport, to the front, since precisely these folding flaps can otherwise be easily folded over to the back by the transport of the article groups or container groups, which is not desired and which would inevitably lead to an impairment of the packaging quality of the shrink-wrapped bundles to be produced.

Much like the rigid guide bars or the guide bars, respectively, which are designed to be height-movable, the movable wrapping members can also be designed to be adjustable in their vertical and/or horizontal position in relation to the transport route. The adjustability in height and/or width is reasonable for the purpose of adaptability to the different sizes of articles or containers, to the different sizes or widths of bundles, etc., which are intended to pass through the heating section.

The apparatus provides that the guide bars extend into the heating section by a defined length such that the folded folding flaps are respectively held in their position and do not re-open. The guide bars can optionally be passed through the entire heating section, or also only through a partial section, since it may suffice, as the case may be, if the folding flaps, which have been placed on top of each other, are not pressed against each other throughout the entire heating section. Optionally, the length of the guide bars can also be variably adjustable. It is furthermore reasonable for the movable wrapping members and/or for the guide bars, which extend into the heating section, to be respectively formed to be heat-resistant and/or to be provided with a heat-resistant coating, in order to reduce their friction or their tendency to adhere to the packaging means. In this manner, it is possible to prevent the heated shrink film from adhering to the guide bars and/or to the adjustable wrapping members and thereby from leading to either the folding state to be impaired or even to the film to be damaged. Suitable materials are available for such coatings, which at the same time provide for a very smooth surface so that the lengths of film can glide easily during the passage of the container arrangements.

The mentioned guide bars can optionally be provided with air exit openings such that air can exit through openings from the guide bars, which extend on at least one longitudinal side of the transport route and/or into the heating section. On the one hand, this air can serve as cooling air for preventing the film flaps of the article groups or container groups, which have been wrapped in film, from adhering or clinging to the guide bars. On the other hand, the air also serves as an air cushion, which can likewise reliably prevent such an adhesion. In addition, the air streaming out of the openings can reduce the friction of the article groups or container groups that glide along the guide bars. The air exit openings can be formed by a multitude of small bores or air nozzles, respectively, in the guide bars, which are designed to be hollow. The guide bars can optionally also be made from a microporous material through which the air can stream out in the desired quantity.

The apparatus can optionally provide that additional application devices for fastening, gluing, and/or welding at least individual folds onto one side or onto both transverse sides of the film-wrapped bundles are assigned to the mechanical folding members or arranged downstream of them, as viewed in the direction of transport. At least individual folds can thus be fastened, glued, or welded onto one side or onto both transverse sides of the film-wrapped bundles. This fastening, gluing, or welding can be carried out for individual folding flaps, for instance, for the top, bottom, and/or lateral folding flaps, or also for a plurality of folding flaps. In this manner, the shrinking is supported by the folding flaps, which have been placed on top of each other, additionally being fixed to one another.

Furthermore, the method allows providing up to four conveyor lines arranged adjacent to each other and respectively having folding members of the same type. In this instance, the guide bars and/or the movable folding members can be respectively arranged in up to quadruple arrangement for up to four parallel conveyor tracks if the heating section is also designed correspondingly wide for receiving up to four article groups or container groups being conveyed in parallel.

In the following passages, the attached figures further illustrate exemplary embodiments of the invention and their advantages. The size ratios of the individual elements in the figures do not necessarily reflect the real size ratios. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged in relation to other elements to facilitate an understanding of the invention.

FIG. 1 shows four schematic views (FIGS. 1A, 1B, 1C, and 1D) of the processing and packaging of container groups into film.

FIG. 2 shows a schematic lateral view of a heating section for producing shrink-wrapped bundles.

FIG. 3 shows a folding module for producing the shrink-wrapped bundles in three schematic views (FIGS. 3A, 3B, and 3C).

FIG. 4 shows two detailed views (FIGS. 4A and 4B) of the folding module according to FIG. 3.

FIG. 5 shows three further detailed views (FIGS. 5A, 5B, and 5C) of the heating section or of the folding module, respectively, for producing the shrink-wrapped bundles.

DETAILED DESCRIPTION OF THE INVENTION

The same or equivalent elements of the invention are designated by identical reference characters. Furthermore and for the sake of clarity, only the reference characters relevant for describing the respective figure are provided. It should be understood that the detailed description and specific examples of the apparatus as well as of the method according to the invention, while indicating preferred embodiments, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

The schematic illustrations in FIGS. 1A to 1D show consecutive method steps in the production of shrink-wrapped bundles according to the invention from groups 10 of assembled articles or containers 12. The schematic perspective view in FIG. 1A and the schematic lateral view in FIG. 1C thus illustrate the transport of up to four groups 10 of assembled beverage containers 12, which are being fed by a film application device 16, which is not described in more detail here, along a transport route 14, which is only symbolically indicated by arrows here. In the film application device 16, the total of four containers 12 of the container group 10, which containers 12 have been assembled into a square or rectangular group, respectively, are wrapped into a length of film 20 in the direction of transport 18, with the length of film 20 being slightly larger than the container group 10 such that, on the one hand, it forms an overlapping section, which is not illustrated in more detail here, in the direction of transport 18. At the same time, lateral overlapping sections 22 are formed in the process of wrapping the container group 10, which overlapping sections 22 each have folding flaps 24 projecting beyond the container group 10 on the sides of the transverse edges, which folding flaps 24 will be folded over and placed on top of each other in the further conveying area of the transport route 14. This is illustrated by the schematic presentation of the container group 10, which is already wrapped into the length of film 20, shown on the right, as viewed in the direction of transport 18, in FIG. 1A, where the overlapping sections 22 of the length of film 20 around the container group 10 have already been partially placed against the sides of the container group 10 by folding over a front folding flap 24 a and a rear folding flap 24 b. By contrast, only the front folding flap 24 a of the overlapping section 22 has already been placed against the container group 10 and folded over in the illustration of FIG. 1C.

The folding processes shown in the FIGS. 1A and 1C are, in particular, supported or carried out, respectively, by means of mechanical folding members 26, which, in the exemplary embodiment shown in FIG. 1B, are formed by guide bars 28, which are arranged on both sides at the longitudinal sides of the transport route 14 such that the container groups 10 can be conveyed passing through between them. It should be noted, however, that the guide bars 28 shown here are not suited for folding over the respectively rear folding flaps 24 b and for placing them against the outer surfaces of the containers of the group 10. Other folding devices are necessary for this purpose such as will be explained in more detail and described in their function and mode of operation by means of the following figures. During the transport of the arrangements 10 through a heating section (see FIG. 2 etc.), the guide bars 28, however, do provide for maintaining the folding state of the folding flaps 24, which have been folded over, and for fixing them to one another or to the outer surface of the length of film 20, respectively, in a shrinking process, which is carried out, in particular, by way of hot air impingement on the container arrangements 10 during their transport through the heating section.

In the illustration in the middle, FIG. 1B presents an optional process of folding over a bottom folding flap 24 c by folding it upward, preferably on both sides of the lateral overlapping sections 22. The right illustration of FIG. 1B furthermore presents an optional process of folding over a top folding flap 24 d by folding it downward, again preferably on both sides of the lateral overlapping sections 22. Fixing the bottom and/or the top folding flaps 24 c and/or 24 d onto the outer surfaces of the container group 10 after folding them over can preferably also be supported by mechanical folding members 26 or by guide bars 28, respectively, which can accompany the transport route 24 on both sides of the conveyed groups 10 in a horizontal course. These further guide bars 28 are however only shown in the left illustration of the presentation of FIG. 1B.

The side and front views of FIG. 1D again show a useful folding process of the lateral overlapping sections 22 of the length of film 20, which has been placed around the container group 10, where first the front and rear folding flaps 24 a and 24 b are folded over (left illustration), after which the bottom folding flaps 24 c (middle side view and middle front view) on both sides and subsequently the top folding flaps 24 d (top right side view; bottom right front view) on both sides can be folded over, optionally respectively supported by suitable mechanical folding members or guide bars, respectively (not illustrated in FIG. 1D).

In order to ensure that the top folding flaps 24 d are the last to be folded over, it can be provided that they are first held in their unwrapped position or unfolded position, respectively, while the remaining folding flaps 24 a, 24 b, and 24 c are folded over, and only subsequently are the top folding flaps 24 d placed laterally against the container group 10. In this manner, it is possible to reliably prevent disordered folding processes in which the top folding flaps 24 d, for instance, can fold down, in particular, while the lateral, i.e. the front and/or the rear folding flaps 24 a and 24 b are being wrapped, and interfere with these folding processes or lead to wrinkles, respectively. If the top folding flaps 24 d are, however, held up by means of suitable devices (not shown here) for as long until the remaining folding flaps 24 a, 24 b, 24 c have been placed against the film-wrapped container groups 10, such potential disruptions are prevented. The fixation of the top folding flaps 24 d can be ensured by way of suitable suction devices, for instance, or optionally also by electrostatic holding force, mechanical holding force, or the like. Optionally, the top folding flaps 24 d can be held in their upper, as yet unfolded position by way of being blown at with compressed air until the remaining folding flaps 24 a, 24 b, 24 c have been placed against the container groups 10, after which the top folding flaps 24 d can then also be placed against the container groups 10 as the last ones.

In this process of placing the lateral overlapping sections 22 on top of each other, an opening 32 can optionally be formed in the middle section of the sides of the wrapped container arrangements 10 between trailing edges 30 of the folding flaps 24 a, 24 b, 24 c, 24 d, which trailing edges 30 face toward each other, as is indicated in the FIGS. 1B and 1D. This opening 32 is commonly also termed film eye, and, as the case may be, it can also grow larger during the impingement with heat in the shrinking process, since the film contracts in the direction toward the bundle edges. It is, however, likewise possible that the trailing edges 30 facing toward each other are placed on top of each other such that they overlap each other and form closed sides without openings 32.

The schematic illustration of FIG. 2 shows a typical section of the transport route 14, which has a heating section 34 arranged downstream from the film application device 16 in the direction of transport 18 for impinging the container groups 10 together with the film wrapping 20 with hot air for the purpose of forming shrink bundles. In the shown exemplary embodiment, the heating section through which the container groups 10, which have been wrapped in film 20, pass in the direction of transport 18, is formed as shrink tunnel 36, which is equipped with devices for the even impingement of the container groups 10 with hot air on all sides. In this instance, the temperatures within the heating section 34 or within the shrink tunnel 36, respectively, are selected such that the film wrapping 20, together with the folding flaps 24 on the sides of the transverse edges, which folding flaps 24 are folded over (cf. FIG. 1), is tightly tensioned around the containers 12 and assembles these in shrink-wrapped bundles 38, within which the containers 12 are held against each other largely stationary and can only carry out minimal movements in relation to each other.

The cooling fans 40 shown in FIG. 2 at the exit of the shrink tunnel 36 serve for cooling the previously heated bundles 38 such that these can be fed in conveying direction to further devices for handling, stacking, palletizing and/or packaging (not shown here).

As is schematically indicated in FIG. 2, the mechanical folding members 26 for fixing the folded folding flaps 24 and/or for holding the folding flaps 24 (cf. FIG. 1) can, in their folded position, extend into the heating section 34 over a partial section 42 of a variable length 44 a or 44 b. The length 44 a of the folding members 26 or of the guide bars 28, respectively, can optionally be very short such that they can already end in a front area of the heating section 34. Optionally, the length 44 b can, however, also be selected such that it corresponds approximately to the length of the heating section 34. Other lengths of the folding members 26 or of the guide bars 28 are also possible. In this context it should be noted that the alternative lengths 44 a and 44 b shown here are to be understood as examples. The selected length 44 a or 44 b can of course conform to the requirements of the respective shrink bundles 38. If the folding flaps 24 adhere to each other or to the outer surfaces of the film wrapping 20, respectively, already after a very short exposure time to the heat impingement, relatively short sections (first length) of the folding members 26 or of the guide bars 28, respectively, will suffice. If the folding flaps 24, however, require a longer exposure time to the heat impingement in order to adhere to each other or to the outer surfaces of the film wrapping 20, respectively, then a longer design (second length) of the folding members 26 or of the guide bars 28, respectively, will be reasonable.

The guide bars 28 can optionally be provided with air exit openings, which are not shown here, such that air can exit through air nozzles or small openings from the guide bars 28, which extend on at least one longitudinal side, preferably on both longitudinal sides into the heating section 34. On the one hand, this air can serve as cooling air, which can prevent the film flaps of the container groups 10, which have been wrapped in film 20, from adhering or clinging to the guide bars 28. On the other hand, the air also serves as an air cushion, which can likewise reliably prevent such an adhesion. In addition, the air streaming out of the openings can reduce the friction of the container groups 10 that glide along the guide bars 28. The air exit openings can be formed by a multitude of small bores or air nozzles, respectively, in the guide bars 28, which are designed to be hollow. Optionally, at least a portion of the guide bars 28 can also be made from a microporous material through which the air can stream out in the desired quantity, in particular in the area of the heating section 34 or at least in sections where the guide bars 28 extend into the heating section 34.

The schematic illustrations of FIGS. 3A, 3B, and 3C present an embodiment variant of a folding module 46 such as is shown in the FIGS. 1A to 1D, which folding module 46 serves for folding over the folding flaps 24 of a container arrangement 10, which has been wrapped in film 20. The folding module 46 is located at the infeed side 48 of the shrink tunnel 36 and is anchored there at horizontal holding members 50, which are fastened to a top side of the infeed opening 52 of the shrink tunnel 36 such that they are arranged above a conveying plane 54 and in parallel to it.

While the schematic perspective view in FIG. 3A gives an overview of the positioning of the folding module 46, the schematic perspective view in FIG. 3B makes a few details of the folding module 46 discernible, such as, for instance, the vertical holding members 58, which are adjustable in their position and which are fastened by means of clampable holders 56 to holding members 50, which run transversely to the conveying direction, with the mechanical folding members 26 or the guide bars 28 (cf. FIG. 1B), respectively, being suspended from the vertical holding members 58. The adjustability of the clampable holders 56 at the cross members 50 allows positioning the folding module 46 as well as varying the distance of the guide bars 28 to each other, whereby their position can be adapted to the width of the respective container arrangement 10.

The schematic lateral view in FIG. 3C as well as the perspective view in FIG. 3B additionally make discernible an adjustment mechanism 60 for the height adjustment of the guide bars 28 as well as for the adjustment of the vertical distance of two parallel guide bars 28 on each side of the folding module 46. The adjustment mechanism 60 comprises upper adjustment wheels 62, which are arranged at the height of the clampable holders 56. The adjustment wheels 62 are torque-proofly connected with vertical shafts 64, which interact with a scissor joint 66 of the adjustment mechanism 60 such that a rotation of the adjustment wheels 62 effects the vertical distance of the two guide bars 28, which are arranged one above another on each side of the folding module 46.

In addition, the FIGS. 3A to 3C make discernible movable wrapping members 68, which are part of the folding members 26 and which serve for folding over the respectively rear folding flaps 24 b of the lateral overlapping sections 22 of a container arrangement 10, which has been wrapped in film 20. Since the movable wrapping members 68 can be better discerned in the detailed views of FIGS. 4A and 4B, the following description for these figures is pointed out here.

The schematic illustrations of FIGS. 4A and 4B thus show the entire folding module 46, which is taken off of and separated from the cross members 50, which are suspended from the longitudinal holding members 50 at the infeed side 48 of the shrink tunnel 36 (cf. FIG. 3). As mentioned, the folding module 46 serves for folding over the folding flaps 24 of a container arrangement 10, which has been wrapped in film 20 (cf. FIGS. 1A to 1D). FIG. 4A thus makes discernible many of the already explained constructional details, such as the vertical holding members 58, which are fastened to the clampable holders 56, and from which the mechanical folding members 26 or the guide bars 28, respectively, are suspended. Clearly discernible in the figure is also the adjustment mechanism 60 for the height adjustment of the guide bars 28 as well as for the adjustment of a vertical distance of two parallel guide bars 28 on each side of the folding module 46. The upper adjustment wheels 62 act via the vertical shafts 64 upon the respective scissor joint 66 of the adjustment mechanism 60 such that a rotation of the adjustment wheels 62 enables varying the vertical distance of the two guide bars 28, which are arranged one above the other on each side of the folding module 46.

The movable wrapping members 68, which are discernible as folding fingers 78 in the FIGS. 4A and 4B, and which are part of the folding members 26 and serve for folding over the respectively rear folding flaps 24 b of the lateral overlapping sections 22 of a container arrangement 10, which has been wrapped in film 20, are located at horizontal frame members 70, which are arranged above the guide bars 28 and also above the adjustment mechanism 60 for the height adjustment of the guide bars 28. The horizontal frame members 70, which are arranged on both sides of the transport route 14 and in parallel to the direction of transport 18, protrude the furthest in the opposite direction from the infeed side 48 of the shrink tunnel 36 and form the longest outrigger of the folding module 46. They receive horizontal pivot shafts 72, the axial direction of which run transversely to the conveying direction 18, and which are respectively driven by electric motors 76 via actuating levers 74 such that the pivot shafts 72 respectively carry out defined oscillating pivoting motions about a defined pivot angle of approximately 40 to 70 degrees. The pivot shafts 72 carry respectively one folding finger 78, which provides for the wrapping motion on the rear folding flap 24 b of each container arrangement 10.

It should be noted here that, with an otherwise largely unchanged constructional design, the movable wrapping members 68 can optionally also carry out rotating movements, where a part of this course of movement serves for folding over the respectively rear folding flaps 24 b of the lateral overlapping sections 22 of the container arrangement 10, which has been wrapped in film 20. In this alternative embodiment variant, the pivot shafts 72 can optionally be directly coupled with the electric motors 76 and be directly driven by them, thus resulting in the continuously circulating rotary motions of the folding fingers 78.

A reasonable pivoting radius of the wrapping members 68 or of the pivoting levers 78, respectively, can reach approximately from a vertical position to an approximately horizontal position aligned approximately in parallel to the conveying direction 18. By their arrangement and their pivoting motions, the pivotable folding fingers 78 with the specified radius of movement can place at least the rear folding flaps 24 b, as viewed in the direction of transport 18, to the front over the previously folded folding flaps 24 a by a pivoting motion immediately before the entrance of the heating section 34 such that the desired enclosing folding state can be produced, which, during the shrinking process in the heating section 34, will then lead to the desired adhesion of the folding flaps 24 to one another, which folding flaps 24 have been placed on top of each other.

Preferably, both the movable wrapping members 68 or folding fingers 78, respectively, and the guide bars 28, which extend into the heating section 34, are respectively formed to be heat-resistant and/or are provided with a heat-resistant coating. In this manner, it is possible to prevent the heated shrink film 20 from adhering to the guide bars 28 and/or to the adjustable wrapping members 68 and thereby from leading to either the folding state to be impaired or even to the film 20 to be damaged.

The schematic front view of FIG. 5A shows the infeed opening 52 of the shrink tunnel 36 with the installed folding module 46, as viewed in the direction of transport 18. This view makes discernible that optionally two folding modules 46 of the same type with folding members 26 respectively of the same type can also be installed (not illustrated here), provided that the transport route 14 through the heating section 34 is sufficiently wide. In this instance, the guide bars 28 and/or the movable folding members 68 can be respectively arranged in double arrangement for two parallel conveyor tracks if the heating section 34 through the shrink tunnel 36 is also designed correspondingly wide for receiving two container groups 10 being conveyed in parallel.

The illustration of FIG. 5A and the detailed view of FIG. 5B show a container arrangement 10 passing by the folding members 26 and by the movable wrapping members 68, with the container arrangement 10 being conveyed along the guide bars 28, which run in parallel on both sides, into the heating section 24 of the shrink tunnel 36. As can be in addition discerned from FIG. 5B, there are lower guide rails 80 for guiding and folding the bottom folding flaps 24 c (cf. FIG. 1B, FIG. 1D), which lower guide rails 80 are arranged on both sides of the container arrangement 10 or of the film-wrapped bundle 38, respectively, and which provide for the desired upward folding movements of the bottom folding flaps 24 c in the infeed section. The middle guide rails 82 arranged above that provide for guiding and folding the front folding flaps 24 a (cf. FIGS. 1A to 1D), while the top guide rails 84 provide for guiding and folding the top folding flaps 24 d. The rear folding flaps 24 b are finally folded by the folding fingers 78 as soon as the arrangement 10 laterally passes by them.

The front view of FIG. 5C, by contrast, shows the reversed view from out of the shrink tunnel 36. The container arrangement 10 shown there moves toward the observer along the guide bars 28 and passes by the folding module 46.

The invention has been described with reference to a preferred embodiment. Those skilled in the art will appreciate that numerous changes and modifications can be made to the preferred embodiments of the invention and that such changes and modifications can be made without departing from the spirit of the invention. It is, therefore, intended that the appended claims cover all such equivalent variations as fall within the true spirit and scope of the invention.

LIST OF REFERENCE CHARACTERS

-   10 Group, container group, container arrangement -   12 Container, beverage container -   14 Transport route -   16 Film application device -   18 Transport direction, conveying direction -   20 Film, length of film, film wrapping -   22 Overlapping section, lateral overlapping section -   24 Folding flap -   24 a Front folding flap -   24 b Rear folding flap -   24 c Bottom folding flap -   24 d Top folding flap -   26 Folding member, mechanical folding member -   28 Guide bar, lateral guide bar -   30 Trailing edge -   32 Opening, film eye -   34 Heating section -   36 Shrink tunnel -   38 Bundle, film-wrapped bundle, shrink-wrapped bundle, shrink bundle -   40 Cooling fan -   42 Partial section -   44 a First length (guide bar) -   44 b Second length (guide bar) -   46 Folding module -   48 Infeed side -   50 Holding member, horizontal holding member, cross member -   52 Infeed opening -   54 Conveying plane -   56 Holder, clamping holder, clampable holder -   58 Holding member, vertical holding member -   60 Adjustment mechanism -   62 Adjustment wheel -   64 Shaft, vertical shaft -   66 Scissor joint -   68 Wrapping member, movable wrapping member -   70 Frame member -   72 Pivot shaft, horizontal pivot shaft -   74 Actuating lever -   76 Electric motor, electric drive motor -   78 Folding finger -   80 Lower guide rail -   82 Middle guide rail -   84 Upper guide rail 

I claim:
 1. A method for producing shrink-wrapped bundles (38), which are formed from groups (10) of assembled articles or containers (12), the method comprising: on a transport route (14) and in the direction of transport (18), wrapping article groups or container groups (10) into a length of film (20) under formation of an overlapping section (22) as well as under formation of folding flaps (24) respectively projecting beyond the article groups or container groups (10) on the sides of the transverse edges; at least partially placing, by means of mechanical folding members (26), the folding flaps (24) projecting on both transverse sides on top of each other under formation of an opening (32) between trailing edges (30) of the folding flaps (24), which trailing edges (30) face toward each other, or under overlapping each other and/or they are placed against the adjacent outer surfaces of the articles or containers; passing, together with the film wrapping (20) and under formation of shrink bundles (38), the article groups or container groups (10) through a heating section (34) within which the article groups or container groups (10), which are wrapped in film (20), are impinged with hot air; wherein at least a part of the folded folding flaps (24) are fixed and/or held in their folded position over a defined length (44 a, 44 b) within the heating section (34) by means of the mechanical folding members (26).
 2. The method as recited in claim 1, in which the folding flaps (24) are respectively folded over and/or held in their folded position by guide bars (28), which are arranged at least on one longitudinal side of the transport route (14).
 3. The method as recited in claim 1, in which at least the rear folding flaps (24 b), as viewed in the direction of transport (18), are folded over about approximately vertical bending edges by means of movable wrapping members (68).
 4. The method as recited in claim 3, in which at least the rear folding flaps (24 b), as viewed in the direction of transport (18), are respectively folded over by means of pivoting levers (78), which are each arranged on at least one side of the transport route (14) to be pivotably movable about an approximately horizontal pivoting axis (72).
 5. The method as recited in claim 1, in which the folded folding flaps (24 a, 24 b, 24 c, 24 d) at the transverse sides of the article groups or container groups (10), which have been wrapped in film (20), are held in their respective positions over a defined length (44 a, 44 b) extending into the heating section (34).
 6. The method as recited in claim 1, in which at least individual folding flaps (24 a, 24 b, 24 c, 24 d) are fastened, glued, or welded onto one side or onto both transverse sides of the film-wrapped bundles (38).
 7. The method as recited in claim 5, in which the respective top folding flaps (24 d) of the article groups or container groups (10) are held in their unwrapped or unfolded position, respectively, at least until folding or wrapping, respectively, the remaining folding flaps (24 a, 24 b, 24 c) of each side, and they are only subsequently placed laterally against the article group or container group (10).
 8. The method as recited in claim 2, in which air exits through openings from the guide bars (28), which extend on at least one longitudinal side of the transport route (14) and into the heating section (34).
 9. An apparatus for producing shrink-wrapped bundles (38) from groups (10) of assembled articles or containers (12), comprising: a transport route (14) to which is assigned a film application device (16) to wrap the respective article groups or container groups (10) into a length of film (20) in the direction of transport (18) under formation of an overlapping section (22) as well as under formation of folding flaps (24) respectively projecting beyond the article groups or container groups (10) on the sides of the transverse edges; and a plurality of mechanical folding members (26) for at least partially placing on top of each other the folding flaps (24) projecting on both transverse sides against the adjacent outer surfaces of the articles or containers, wherein an opening (32) is formed between trailing edges (30) of the folding flaps (24), which trailing edges (30) face toward each other, wherein the transport route (14) comprises a heating section (34) downstream of the film application device (16), as viewed in the direction of transport (18), for impinging the article groups or container groups (10) together with the film wrapping (20) with hot air for the purpose of forming shrink bundles (38); and wherein the plurality of mechanical folding members (26) extend into the heating section (34) for the purpose of fixing the folded folding flaps (24) and/or of holding the folding flaps (24) in their folded position at least over a partial section (42) of a defined length (44 a, 44 b).
 10. The apparatus as recited in claim 9, in which the folding members (26) comprise guide bars (28) on at least one longitudinal side of the transport route (14) or are formed by such guide bars (28).
 11. The apparatus as recited in claim 10, in which the guide bars (28), which are arranged on at least one longitudinal side of the transport route (14), are height-adjustable and/or adjustable in their horizontal position in relation to the transport route (14).
 12. The apparatus as recited in claim 9, in which the folding members (26) comprise movable wrapping members (68) or are formed by such movable wrapping members (68).
 13. The apparatus as recited in claim 12, in which the movable wrapping members (68) comprise at least one pivoting lever or folding finger (78), which is arranged on at least one side of the transport route (14) to be pivotable about an approximately horizontal pivoting axis (72).
 14. The apparatus as recited in claim 13, in which a pivoting radius of the wrapping members (68) reaches approximately from a vertical position to an approximately horizontal position aligned approximately in parallel to the conveying direction (18).
 15. The apparatus as recited in claim 14, in which the wrapping members (68) respectively carry out rotating movements.
 16. The apparatus as recited in claim 12, in which the movable wrapping members (68) are formed to be adjustable in their vertical and/or horizontal position in relation to the transport route (14).
 17. The apparatus as recited in claim 10, in which the guide bars (28) extend into the heating section (34) by a defined length (44 a, 44 b).
 18. The apparatus as recited in claim 10, in which the movable wrapping members (68) and/or the guide bars (28), which extend into the heating section (34), are respectively formed to be heat-resistant and/or are provided with a heat-resistant coating.
 19. The apparatus as recited in claim 10, in which the guide bars (28) are provided with air exit openings, at least in the sections extending into the heating section (34), for the purpose of letting out cooling air.
 20. The apparatus as recited in claim 9, in which additional application devices for fastening, gluing, and/or welding at least individual folds or folding flaps (24) onto one side or onto both transverse sides of the film-wrapped bundles (38) are assigned to the mechanical folding members (26) or arranged downstream of them, as viewed in the direction of transport (18).
 21. The apparatus as recited in claim 9, in which up to four or more conveyor lines (14), each with folding members (26) of the same type, are provided, which conveyor lines (14) are arranged adjacent to each other. 